The present invention relates generally to a constant volume combustion device including detonative combustion. More specifically, one form of the present invention is a combustion unit having a high pressure rise, a near time-steady inflow and outflow, while being self cooled. The constant volume combustor has properties of pulse detonation and wave rotor technologies. Although the present invention was developed for use as a combustor within a gas turbine engine, certain applications may be outside of this field.
One of the next big challenges in the area of commercial and military flight is the improvement in fuel economy as flight speeds increase well into the supersonic range. In order to address fuel consumption goals there will be continued engineering advancements in compressor and turbine aerodynamics, higher temperature materials, improved cooling schemes, and the utilization of lightweight materials. It is recognized that the engineering and scientific community should continue to develop greater efficiency for engine components, however more revolutionary change may be required to meet the anticipated future demands for gas turbine engines.
The present application is directed to more revolutionary change through a combustion apparatus utilizing pulsed detonation and wave rotor technologies. Since the 1940's wave rotors have been studied by engineers and scientists and thought of as particularly suitable for a propulsion system. A wave rotor is generally thought of as a generic term and describes a class of machines utilizing transient internal fluid flow to efficiently accomplish a desired flow process. Wave rotors depend on wave phenomena as the basis of their operation, and these wave phenomena have the potential to be exploited in novel propulsion systems, which include benefits such as higher specific power and lower specific fuel consumption. Pulse detonation engines have been researched as a replacement, for rockets and as an alternative propulsion system in gas turbine engines. However, a significant drawback with pulse detonation has been the unsteady flow produced due to the sequencing of detonations to produce thrust or combustion. This unsteady flow is envisioned to result in a multiplicity of mechanical and aerodynamic based challenges.
There are a variety of wave rotor devices that have been conceived of over the years. However, until the present invention the potential for wave rotor and pulse detonation technologies has not been realized. The present invention harnesses the potential of wave rotor and pulse detonation technology in a novel and unobvious way.